EN 17243:2020
(Main)Cathodic protection of internal surfaces of metallic tanks, structures, equipment, and piping containing seawater
Cathodic protection of internal surfaces of metallic tanks, structures, equipment, and piping containing seawater
This document specifies the requirements and recommendations for cathodic protection systems applied to the internal surfaces of metallic tanks, structures, equipment and piping containing natural or treated seawater or brackish waters to provide an efficient protection from corrosion.
Cathodic protection inside fresh water systems is excluded from this document. This is covered by EN 12499.
NOTE EN 12499 covers internal cathodic protection for any kind of waters, including general aspects for seawater but excluding industrial cooling water systems. This document specifically details applications in seawater and brackish waters.
Kathodischer Schutz der inneren Oberflächen von metallischen Tanks, Strukturen, Ausrüstung und Rohrleitungen die Meerwasser enthalten
Dieses Dokument legt die Anforderungen und Empfehlungen für kathodische Korrosionsschutzsysteme fest, die auf Innenflächen von metallischen Tanks, Anlagen, Anlagenteilen und Rohrleitungen, die naturbelassenes oder behandeltes Meerwasser oder Brackwasser enthalten, angewendet werden, um dort einen wirksamen Korrosionsschutz zu bieten.
Der kathodische Korrosionsschutz von Frischwassersystemen fällt nicht in den Anwendungsbereich dieses Dokuments. Dies wird von EN 12499 abgedeckt.
ANMERKUNG EN 12499 enthält Informationen zum kathodischen Korrosionsschutz von Innenflächen in allen Arten von Wasser, einschließlich allgemeiner Aspekte für Meerwasser, jedoch ausschließlich industrieller Kühlwassersysteme. Dieses Dokument beschreibt gezielt Anwendungen in Meerwasser und Brackwasser.
Protection cathodique des surfaces internes des réservoirs, ouvrages, équipements et tuyauteries métalliques contenant de l’eau de mer
Le présent document spécifie les exigences et les recommandations relatives aux systèmes de protection cathodique appliqués aux surfaces internes des réservoirs, ouvrages, équipements et tuyauteries métalliques contenant de l’eau de mer naturelle ou traitée ou des eaux saumâtres afin d’assurer une protection efficace contre la corrosion.
La protection cathodique interne des systèmes d’eau douce est exclue de la présente norme. Elle est couverte par l’EN 12499.
NOTE L’EN 12499 couvre la protection cathodique interne pour tous les types d’eaux, y compris les aspects généraux pour l’eau de mer, à l’exclusion des systèmes industriels de refroidissement par eau. Le présent document détaille spécifiquement les applications en eau de mer et en eaux saumâtres.
Katodna zaščita notranjih površin kovinskih rezervoarjev, konstrukcij, opreme in cevovodov, ki vsebujejo morsko vodo
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2020
Katodna zaščita notranjih površin kovinskih rezervoarjev, konstrukcij, opreme in
cevovodov, ki vsebujejo morsko vodo
Cathodic protection of internal surfaces of metallic tanks, structures, equipment, and
piping containing seawater
Kathodischer Schutz der inneren Oberflächen von metallischen Tanks, Strukturen,
Ausrüstung und Rohrleitungen die Meerwasser enthalten
Protection cathodique des surfaces internes des réservoirs, ouvrages, équipements et
tuyauteries métalliques contenant de l’eau de mer
Ta slovenski standard je istoveten z: EN 17243:2020
ICS:
47.020.30 Sistemi cevi Piping systems
77.060 Korozija kovin Corrosion of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 17243
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2020
EUROPÄISCHE NORM
ICS 47.020.30; 77.060
English Version
Cathodic protection of internal surfaces of metallic tanks,
structures, equipment, and piping containing seawater
Protection cathodique des surfaces internes des Kathodischer Schutz der inneren Oberflächen von
réservoirs, ouvrages, équipements et tuyauteries metallischen Tanks, Strukturen, Ausrüstung und
métalliques contenant de l'eau de mer Rohrleitungen die Meerwasser enthalten
This European Standard was approved by CEN on 11 November 2019.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17243:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Competence of personnel . 7
5 General considerations . 7
6 Cathodic protection criteria . 9
7 Design . 11
8 Galvanic anodes system . 18
9 Impressed current systems . 26
10 Commissioning, operation and maintenance . 30
Annex A (informative) Environmental checklist . 36
Annex B (informative) Guidance on design values for internal cathodic protection for seawater
containing equipment . 38
B.1 Typical design cathodic current densities . 38
B.2 Coating breakdown factor of protective paint systems . 39
Annex C (informative) Calculation of potential distribution inside a pipe or tube . 40
C.1 Potential distribution inside a pipe (ignoring anode resistance) . 40
C.2 Potential distribution inside a pipe (with anode resistance) . 40
C.3 Potential distribution inside a tube . 41
Annex D (informative) Design of galvanic anode systems . 42
D.1 Anode resistance formulae . 42
D.2 Calculation of the anode resistance at the end of life . 43
D.3 Electrolyte resistivity . 44
D.4 Galvanic anode current output . 46
D.5 Anode life . 47
D.6 Minimum net weight requirement . 47
Annex E (informative) Typical electrochemical characteristics of impressed current anodes . 48
Annex F (informative) Design of impressed current systems . 49
F.1 Internal cathodic protection of tanks . 49
F.2 Evaluation of the maximum length of a rod anode projecting into the water flow for
mechanical integrity . 50
Bibliography . 52
European foreword
This document (EN 17243:2020) has been prepared by Technical Committee CEN/TC 219 “Cathodic
protection”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2020, and conflicting national standards shall
be withdrawn at the latest by September 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
Introduction
Metallic structures containing seawater or brackish waters are exposed to the risk of corrosion. Even
when a coating is applied to reduce this risk, cathodic protection (CP) is usually used to ensure corrosion
control during the structure design life. This is especially important in the presence of galvanic couples
between various metals and alloys because corrosion is then concentrated to the less noble material.
Cathodic protection works by supplying sufficient direct current to the internal surface of the structures
in contact with water in order to change the structure to electrolyte potential to values where the
corrosion rate is insignificant.
The general principles and theoretical aspects of cathodic protection in seawater are detailed in
EN 12473.
1 Scope
This document specifies the requirements and recommendations for cathodic protection systems applied
to the internal surfaces of metallic tanks, structures, equipment and piping containing natural or treated
seawater or brackish waters to provide an efficient protection from corrosion.
Cathodic protection inside fresh water systems is excluded from this document. This is covered by
EN 12499.
NOTE EN 12499 covers internal cathodic protection for any kind of waters, including general aspects for
seawater but excluding industrial cooling water systems. This document specifically details applications in seawater
and brackish waters.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 12473, General principles of cathodic protection in seawater
EN 12496, Galvanic anodes for cathodic protection in seawater and saline mud
EN 12499, Internal cathodic protection of metallic structures
EN 13509, Cathodic protection measurement techniques
EN ISO 8044, Corrosion of metals and alloys — Basic terms and definitions (ISO 8044)
EN ISO 9606-1, Qualification testing of welders — Fusion welding — Part 1: Steels (ISO 9606-1)
EN ISO 15257, Cathodic protection — Competence levels of cathodic protection persons — Basis for
certification scheme (ISO 15257)
EN ISO 15607, Specification and qualification of welding procedures for metallic materials —General rules
(ISO 15607)
EN ISO 15609-1, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 1: Arc welding (ISO 15609-1)
3 Terms and definitions
For the purposes of this document the terms and definitions given in EN 12473 and EN ISO 8044 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp/ui
3.1
anode redundancy factor
multiplier applied to the theoretical number of anodes to allow for anode damage and failures for
ensuring that protection will continue to be achieved when one or more anodes are lost, without
modifying the unit weight of anodes
3.2
back electro motive force
e.m.f
overvoltages generated at anode and cathode interfaces at the operating conditions
3.3
cathodic protection zone
CP zone
part of the structure that can be considered independently with respect to cathodic protection design
3.4
coating breakdown factor
f
c
ratio of cathodic current density for a coated metallic material to the cathodic current density of the bare
material
3.5
critical crevice potential
potential more positive than the potential which there is a risk of initiation of crevice corrosion for a given
environment and crevice geometry
3.6
driving voltage
difference between the structure to electrolyte potential and the anode to electrolyte potential when the
cathodic protection is operating
3.7
over-polarization
occurrence in which the structure to electrolyte potentials are more negative than those required for
satisfactory cathodic protection
Note 1 to entry: Over-polarization provides no useful function and can even cause damage to the structure such as
cracking due to hydrogen embrittlement of sensitive materials or coating disbondment.
Note 2 to entry: Often incorrectly referred to as over-protection.
3.8
ullage factor
u
f
ratio of the surface area of a ballast tank which may be in contact with water to the total surface area
Note 1 to entry: When the entire surface area may be wetted, u = 1.
f
3.9
wetting factor
k
fraction of structure design life when the internal surface of a tank or a structure is in contact with water
Note 1 to entry: When the tank is permanently filled with water, k = 1.
Note 2 to entry: For changing conditions an average value can be considered.
Note 3 to entry: Also known as loading factor, see Reference [1] in the Bibliography.
3.10
hydrogen embrittlement
process resulting in a decrease of the toughness or ductility of a metal due to absorption of hydrogen
3.11
hydrogen stress cracking
HSC
cracking that results from the presence of hydrogen in a metal and tensile stress (residual and/or
applied)
Note 1 to entry: HSC describes cracking in metals which may be embrittl
...
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